1. Field of the Invention
The present invention relates to a lens-fitted photo film unit with a flash device and a method of flash lighting thereby.
2. Description Related to the Prior Art
The applicant produces and sells a lens-fitted photo film unit in which an unexposed filmstrip is preloaded. There is a type of the lens-fitted photo film unit, which has a flash device so as to take pictures in the night or the room. The flash device of the lens-fitted photo film unit should have a simple structure as the lens-fitted photo film unit can be readily bought.
The flash device is constructed of a flash circuit board with a flash circuit mounted thereon for controlling charge and discharge, and a flashlight projector unitized and attached to the flash circuit board for projecting a flashlight. The flashlight projector is substantially constructed of a flash tube, a reflector and a transparent protector. The flash tube emits a flashlight corresponding to a trigger signal. The reflector reflects the flashlight such that the flashlight projector may project the flashlight forwards. The protector is disposed to protect the flash tube and the reflector, and determine a characteristic of lighting distribution of the flashlight. In order to increase an effect of the flashlight and project the flashlight at the same strength in a photographic area, the protector makes a projection axis of the flashlight projector coincide with a center of the photographic area.
However, if a flashlight photograph is carried out with the lens-fitted photo film unit, the subjects in a smaller distance, for example persons in a center of the photographic area, are often overexposed, and the backgrounds to be a side of the area are underexposed due to larger distance. In order to improve the quality of pictures, an automatic flash device is used. However, provision of a photometric element and control circuits increases the cost for production of the lens-fitted photo film unit becomes higher. Further, the effect of the automatic flash device is not so much.
When the flashlight photograph is carried out with a camera, it is known to softly illuminate the subject in effect of a bounce light. In this case, a direction in which the flashlight projector is tended is manually adjusted, and an exposure amendment must be made through operating an exposure adjustment member provided for the camera, depending on the direction in which the flashlight is projected.
However, for low cost of production the lens-fitted photo film unit, it is difficult to provide the exposure adjustment member and the swingable structure of the flashlight projector.
An object of the present invention is to provide a lens-fitted photo film unit that is produced at a low cost and a method of flash lighting thereby.
Another object of the present invention is to provide a lens-fitted photo film unit and a method of flash lighting thereby such that a subject in a center of a photographic area may not be overexposed.
A still another object of the present invention is to provide a lens-fitted photo film unit and a method of flash lighting thereby such that a background may not be underexposed.
The last object of the present invention is to provide a lens-fitted photo film unit so as to obtain the effect of the bounce light to a subject in a larger distance when a flashlight photograph is carried out in a room.
The above and other objects are achieved while a flashlight projector projects a flashlight such that an intensity of the flashlight may be at the maximum above and/or below a photographic area. Preferably, the intensity of the flashlight is 1.0-1.5 LV higher on upper and/or lower limits of a photographic area than in a center thereof. In the flashlight projector, a flash tube is disposed on a projection axis of the flashlight projector in an inner side of a reflector formed in a nearly half-elliptical shape. To a front side of the reflector is attached a protector.
In the present invention, the protector is provided with a regulation portion for determining a distribution of the flashlight. The regulation portion reflects a part of the flashlight emitted into a center of the photographic area such that the part of the flashlight may tend to an outside of the photographic area, and the intensity of the flashlight may be decreased in the center of the photographic area. In another embodiment of the present invention, a distance between the protector and the flash tube is larger than an opening width of the reflector. In a still another embodiment, the projection axis of the flashlight projector is inclined upwards or downwards.
In the lens-fitted photo film unit of the present invention, an ISO sensitivity of a used filmstrip, an exposure condition, and the intensity of the flashlight are previously determined. Accordingly, if the distribution of the flashlight is adjusted, the exposure amount can be higher on upper and lower edges of a frame on the filmstrip than in the center thereof. Thus the main subject that is usually photographed in the center of the frame is not overexposed, and the background in upper and lower sides of the frame is not underexposed. Further, a scene is three-dimensionally photographed in the flashlight in a room, as the flashlight reflects on a ceiling, a floor and a wall such that a depth to the main subject may be clearer, and the background can be softly illuminated in the bounce light. As the present invention has a simple structure, the cost for production does not increase.